Have you ever wondered what our solar system looked like 3.8 billion years ago? Were the planets we know today anything like ...

Discover the order of planets in the solar system. From Mercury to Neptune, explore our solar system and learn more about our cosmic home.

Close stellar encounters could change the structure of our planetary system, potentially dooming Earth or other worlds to ...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to [email protected]. Are planets in the solar system that are ...

Astronomers have discovered a rare solar system in the Milky Way with six planets orbiting in perfect rhythm like a cosmic orchestra.

Centimeter-sized pebbles have been detected in protoplanetary discs using e‑MERLIN, filling in a critical phase of planet ...

Such synchrony may occur when planets first form, but astronomers theorize that as time goes on, its likely for orbits to get knocked out of rhythm.

Earth Day is April 22 — think you know the planets? Test your knowledge of the solar system in this fun and engaging lifestyle quiz — and see how well you do!

All eight of the solar system’s “major” planets appear in this illustration, but the actual number of planetary bodies orbiting our star is far greater.

Smithsonian Astrophysicist and Harvard Lecturer Matthew Holman discusses the search for undiscovered planets at the edge of the solar system.

Astronomers have discovered a rare in-sync solar system with six planets moving like a grand cosmic orchestra, untouched by outside forces since their birth billions of years ago. The find ...

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky ...